Hair does not show up in final render
The problem is you've set the Shape parameter value to 1 in the Cycles Hair Settings. According to the Blender wiki:


  A shape parameter that controls the transition in thickness between the root and tip. -1 gives a constant thickness equal to the root, 0 gives a linear transition and 1 gives an instantaneous transition to the tip radius. 


What happens when you set that value to 1 is it makes the thickness of the hair strand the same as the tip radius, which in this case is 0. That's why it didn't show up in the render.

Change the Shape parameter value to 0 and it'll work.